This would definitely be desirable - a lot of people expect LastCalc to have this kind of functionality already.
At the heart of LastCalc is a best-first backtracking "parser", which is implemented here:
The idea is that you start with a list of tokens, and then attempt to apply parsers to them, a parser being something that transforms one set of tokens into another. The goal is to reduce it down to a single token, which is hopefully the answer.
I think the same mechanism can be applied to solving equations, so for example, if we have a way to represent an equation, we could have a parser that transforms one equation representation into another "better" one, perhaps by factorization, or another algebraic operation ("better" is defined by the goal, such as isolating a variable).
In any case, I think it makes sense to reuse LastCalc's built-in parsing mechanism if possible rather than graft on an independent system.
Ian.